[DSL] 2 Wire uncancelled echo , dsl stats
I'm using a 2 wire 2700HG-B in bridge mode. Connected with a profile of 6/8. Dry loop. Whenever I power the modem on, it connects with decent line quality. The 2wire is unlocked and I have access to the mdc pages.
The 2wire states:
Downstream: SNR 10dB w/39 dB attenuation Power 19.7 dBm
Upstream: SNR 15dB w/23 dB attenuation Power 11.9 dBm
Detailed stats are good, no CRC's very few errors of any kind. Basically a good connection. DSL diagnostics look great.
Over the period of a day or two, the connection slowly degrades. The modem seems to hold a connection, but every once and a while I will experience appears to be a noisy line. Lots of cell header errors, crc's, uncorrectable block along with "Uncancelled echo" as high as +10 to +30 dB ! Sometimes its worse that others, this doesn't appear to be tied to a particular time of day, or weather pattern etc etc.
The strange thing is , if I reset the modem ( reboot ) I go back to solid line quality, zero errors, uncancelled echo -11db .. all is well again and the cycle repeats. So I'm thinking this must be an issue with either the 2wire modem, or the dslam itself.
So my question is:
How could the 2wire show terrible stats with all kind of errors, crc's, uncancelled echo, yet all this disappears after reboot? ( I have to reboot, a retrain does not fix the issue )
Have you tried another modem to see if the same thing happens? Your modem may be on its way out.
|reply to tbalon |
I experienced something similar recently. In my case, the problem were the wires. The technician switched my DSL on the other pair I had and things got fixed. As Mike suggested, trying a different modem, at the demarc if possible, is a good way to see if the line is the problem.
I had a Bell Tech out about a week ago. He tested the wires from the dslam to our dmarc. He said the "wires tested perfect". He offered to switch me to a different pair. He tested the other pair and said there was no difference (in his test results). So he kept me on the original pair. He kept saying there is nothing wrong with the wire. It tests perfect.
The wire to the house is new ( less than 5 years ). In our case the dmarc is on the outside of the house. The wires go through the wall, and directly to a bell ( corning ) splitter and then to the 2wire. Total length is only about 3 ft. All new wiring.
I will try a new modem this week and see what I find.
Let us know how it goes.
Ok, so I finally have had the time to get a new modem and make a comparison.
The new modem is another 2Wire. This is a newer modem with the singtel firmware ( unlocked ).
This modem, like the older 2Wire, will show "uncancelled echo" and will drop speed to improve its snr. Unlike the older modem, the new modem does not magically go back to being fine after a reboot.
With the older 2Wire, when the stats got bad, I could use the MDC page to reboot the modem and the stats would magically improve. With the new modem, a reboot ends up syncing at the same rate with slightly better snr, but still shows "uncancelled echo"
So I suppose the older modem & firmware may of had some issues. The new modem will reflect similar line conditions after a reboot where the old one would show a perfect line.